Field of the Invention:
The present invention relates to a haptic operating device having a transmission apparatus and, in particular, a force or torque transmission apparatus, wherein the transmission between a first component and at least one second component which is stationary or moves relative to the first component is able to be changed by influencing the transmission properties between the components. The haptic operating device according to the invention can be used in various technical fields, for example for operating technical equipment such as vehicles or industrial installations or for operating washing machines, kitchen appliances, radios, hi-fi systems or other devices.
In one embodiment of the force or torque transmission, there is provided a magnetorheological transmission in which the transmission property is affected by a magnetorheological fluid that is subjected to a magnetic field. Magnetorheological fluids have very fine ferromagnetic particles, for example carbonyl iron powder, distributed in an oil, for example. Spherical particles having a production-related diameter of 1 to 10 micrometers are used in magnetorheological fluids, in which case the particle size is not uniform. If a magnetic field is applied to such a magnetorheological fluid, the carbonyl iron particles of the magnetorheological fluid are concatenated along the magnetic field lines, with the result that the rheological properties of the magnetorheological fluid (MRF) are considerably influenced depending on the form and strength of the magnetic field.
With regard to the background relating to the embodiments of the invention with the magnetorheological transmission, reference is had to the above-noted prior applications and to information detailed therein.
It has been found during many tests that a haptic operating element can be used commercially as a standard product for infotainment in automobiles, for rotating actuators on smart devices or as an actuator on devices (for example: oscilloscope), for example, virtually only when the base torque (idling torque with the magnetic field switched off; off-state torque) is less than 0.1 Newton meters (Nm). This applies to typical rotary knob diameters of 30, 40 or 50 mm. If a particularly small rotary knob diameter (for example <5 or 10 mm) is used, a base torque considerably lower than 0.1 Nm is very advantageous and necessary.
Haptic operating elements, in particular rotating actuators in vehicles or on smart devices, require, for standard use which is accepted by the user, a base torque which is many times smaller than in the prior art (MRF brakes according to the shearing principle); these base torques are below 0.2 Nm and better less than 0.1 Nm and ideally below 0.05 Nm. Fingers are very sensitive in this regard. For comparison, the haptic operating range (a fine latching pattern) of a known and purely mechanical rotating actuator (benchmark in automobiles) having a knob diameter of approximately 50 mm is between approximately 0.01 Nm (base torque) and a maximum torque of 0.05 Nm (peak ripple). A conventional infotainment rotary knob in the center console (rotating actuator with a rotary knob diameter of 50 mm, for example) with a base torque of 0.06 Nm is not accepted by many automobile manufacturers (cannot be commercially implemented). The necessary blocking (at least 5 Nm, for example simulation of an end stop or the position “P” in the gear selector switch) must then be produced using an additional locking pin (electrically actuated lifting magnet), for example.
A preferred object is therefore to provide an adaptive operating element, the braking torque of which can preferably be set between 0.02 Nm (or less) and 5 Nm (=operating range) in the millisecond range. A factor in the region of 250 between the base torque and the maximum torque is therefore required, which is more than 12 times more than that in the prior art.
In the automotive industry in particular, the intention is to reduce the number of operating knobs in the vehicle since the number has greatly increased on account of the multiplicity of functions. The aim is to substantially display only the currently required information and switching options. On the other hand, the customer should not have to enter and browse the menus too much in order to be able to carry out necessary functions. Therefore, the user must often be able to operate a haptic operating element without the use of force.